230
14 New Zealand Palaeodemography
Palaeodemography is concerned with such issues as estimating demographic
parameters from past populations (primarily from skeletons in an archaeological
context) and/or making deductions regarding the health of individuals in those
populations. The most basic parameters are age-specific fertility in women and
age-specific survival rates of both sexes, from which life tables can be constructed.
Osteologists face considerable problems with the development of reliable age
indicators in skeletons which can be used to relate skeletal morphology to chronological age. The determination of age-specific fertility rates for women depends on
the fact that macro-anatomical alterations may occur at the pelvic bone, in the form
of pitting, as a consequence of pregnancy and childbirth. The number of pregnancies/births may be estimated from what is variously described as pitting or scoring
at two sites, the posterior pubic symphysis and the preauricular groove of the ilium.
Age-specific fertility rates are then derived by relating the total number of pregnancies/births over the life of a woman to her age at death. This method is not without
difficulties. Pitting can arise in nullipara and, further, its traces can gradually become
less pronounced over the years following a birth. A computer simulation study by
Brewis [1], however, tended to confirm osteologically based estimates.
There are further difficulties in the use of statistical techniques for handling both
indicators relating to survival rates and indicators relating to fertility rates. A good
account of some of the ideas, techniques and problems is provided in Hoppa and
Vaupel [2].
14.2 New Zealand Palaeodemography
Because of endemic problems with the preservation of prehistoric skeletons in New
Zealand, palaeodemography has been limited to studies of Maori skeletons from
disparate times and locations. Estimations of fertility in prehistoric New Zealand
have been made by Houghton [3], Phillipps [4], Sutton [5] and Visser [6]. Progress
has been aided by studies by Houghton [7] of scoring of pelvic bones. Estimates of
average age at death were given by Houghton [3] and by Simpson [8] and Sutton
[9]. The most detailed New Zealand palaeodemographic study published to date, by
Brewis, Molloy and Sutton [10], builds on the above. It called on an unusually large
cohort of 172 skeletons.
As the authors note, when their study was published, the date of first colonization was widely believed to be AD 750–950. As we have seen, this date has since
moved some centuries towards the present, with current wide acceptance of Atholl
Anderson’s claim in 1991 for a 12th century first settlement [11]. This claim was
supported by his dismissal of the numerous radiocarbon dates, indicating earlier settlement, on the grounds of a lack of adequate chronometric hygiene. We have argued
that a late settlement requires unrealistically high population growth rates to reach
the population estimates of 155,000 and 166,000 in 1801, at the dawn of European
settlement, made by John Rutherford [12] and of 175,000 made by Dorothy Urlich
[13]. For a modest initial number of settlers (prehistorians usually posit only 50 or
14 New Zealand Palaeodemography
Palaeodemography is concerned with such issues as estimating demographic
parameters from past populations (primarily from skeletons in an archaeological
context) and/or making deductions regarding the health of individuals in those
populations. The most basic parameters are age-specific fertility in women and
age-specific survival rates of both sexes, from which life tables can be constructed.
Osteologists face considerable problems with the development of reliable age
indicators in skeletons which can be used to relate skeletal morphology to chronological age. The determination of age-specific fertility rates for women depends on
the fact that macro-anatomical alterations may occur at the pelvic bone, in the form
of pitting, as a consequence of pregnancy and childbirth. The number of pregnancies/births may be estimated from what is variously described as pitting or scoring
at two sites, the posterior pubic symphysis and the preauricular groove of the ilium.
Age-specific fertility rates are then derived by relating the total number of pregnancies/births over the life of a woman to her age at death. This method is not without
difficulties. Pitting can arise in nullipara and, further, its traces can gradually become
less pronounced over the years following a birth. A computer simulation study by
Brewis [1], however, tended to confirm osteologically based estimates.
There are further difficulties in the use of statistical techniques for handling both
indicators relating to survival rates and indicators relating to fertility rates. A good
account of some of the ideas, techniques and problems is provided in Hoppa and
Vaupel [2].
14.2 New Zealand Palaeodemography
Because of endemic problems with the preservation of prehistoric skeletons in New
Zealand, palaeodemography has been limited to studies of Maori skeletons from
disparate times and locations. Estimations of fertility in prehistoric New Zealand
have been made by Houghton [3], Phillipps [4], Sutton [5] and Visser [6]. Progress
has been aided by studies by Houghton [7] of scoring of pelvic bones. Estimates of
average age at death were given by Houghton [3] and by Simpson [8] and Sutton
[9]. The most detailed New Zealand palaeodemographic study published to date, by
Brewis, Molloy and Sutton [10], builds on the above. It called on an unusually large
cohort of 172 skeletons.
As the authors note, when their study was published, the date of first colonization was widely believed to be AD 750–950. As we have seen, this date has since
moved some centuries towards the present, with current wide acceptance of Atholl
Anderson’s claim in 1991 for a 12th century first settlement [11]. This claim was
supported by his dismissal of the numerous radiocarbon dates, indicating earlier settlement, on the grounds of a lack of adequate chronometric hygiene. We have argued
that a late settlement requires unrealistically high population growth rates to reach
the population estimates of 155,000 and 166,000 in 1801, at the dawn of European
settlement, made by John Rutherford [12] and of 175,000 made by Dorothy Urlich
[13]. For a modest initial number of settlers (prehistorians usually posit only 50 or